Non-Renewable Energy

Non-Renewable Sources of Energy

Non-Renewable energy sources are those which have been created by natural processes over a long period of time, and which will not be replenished within a timescale that humans find useful.

Examples are:

Coal

Solid carbon residues of long-dead organic matter. Available in many places of the world in large quantities. It is a very dirty fuel, causing of the world's worst air pollution, and contributing very much to the Greenhouse Effect, responsible for climate change. Coal is used to produce 41% of the world's electricity.

In one second, a coal-burning power station burns 2 GJ of energy. This is about 80 tonnes of coal per second! The 3.4 billion tonnes of coal burnt in the world in 2002 produced 23% of the world's total energy needs.

It takes about 500 kg of coal to power a computer for one year.
Google alone uses the equivalent electrical output of a whole power station to power its network of servers around the world.

Oil

A liquid hydrocarbon, which provides many fuel products, and is the base material for plastic. It is being phased out as a fuel for electricity production, due to its decreasing availability and increasing price.

Oil causes serious damage to sensitive ecosystems when it is accidentally released, from ships or undersea wells. Oil is a major contributor to city smog, acid rain, and global warming. The use of shale oil from rock strata will increase the environmental damage caused by oil even more.

Oil is used to produce 5% of the world's electricity.

Natural gas

A hydrocarbon gas, methane, which is used for heating and cooking. This is the cleanest and most efficient of the fossil fuels, but, like oil, its reserves are being depleted rapidly. Europe imports nearly all of its gas from Russia and North Africa via enormous pipeline networks. Gas is used to produce 21% of the world's electricity.

CO2 Emissions

The biggest problem with fossil fuels is the emission of pollutants. Along with sulphur and nitrous oxide, which produce acid rain, and several other nasties, all fossil fuels produce CO2 in large quantities. CO2 is responsible for global warming and the loss of stable climate around the world.

CO2 emissions: 0.963 kg CO2/kWh for coal power, 0.881 kg CO2/kWh for oil, or 0.569 kg CO2/kWh for natural gas. From these statistics, you can see that coal is much less efficient than the other fossil fuels, and methane gas is the most efficient.

Future Trends

Traditionally, fossil fuels have been the main resources for human energy needs, but gradually cleaner renewable alternatives are replacing them. This is for environmental, economic, and political reasons.

In 2008, the price per barrel of oil went up to over 100 dollars. As the wars in the Middle East and conflicts and tensions in other oil-exporting countries, such as Libya and Russia, increase, the security of supply of oil is threatened. It is possible to store only a limited amount of oil (about 150 days worth), so economies are very dependent on cotinuous supplies for fuel, but also for industries like pharmaceuticals, plastics, fertilisers, all of which are based on mineral oil.

In the second half of 2014, production around the world slowed considerably. Factories were producing less, because consumers were not buying as much as they were before, because of the economic downturn. With less production, there is less oil consumed by industry. This causes the market to be swamped with cheaper oil supplies, and the price came down to less than 100 dollars, for the first time in 6 years.

One reason for the over-production of oil is the exploitation of oil and gas resources found in strata of rock, usually shale, which previously had been too expensive to use. This shale oil and gas extraction is extremely damaging to the environment, and effectively reverses any gains that had been achieved in the past decades to reduce fossil fuel dependency and convert economies to environmentally-friendly alternatives.

For more information on shale oil, see the article on ScienceLibrary.info: Fracking.

CHP Combined Heat And Power

Also known as cogeneration, CHP is a technology which is used to gain more efficiency from a power station. As the name suggests, both electrical power and useful heat is generated by the burning of fuel.

Combined cooling, heat and power (CCHP), also known as trigeneration, is a system which obtains electrical power, useful heat and cooling from an energy source. The source can be the burning of a fuel or solar heat collector. Some of the heat is used for cooling, such as in an absorption refrigerator. CCHP have higher efficiency rates than CHP plants.

In CHP, what would otherwise be waste heat in the power generation cycle is utilised, often for district heating (CHPDH combined heat and power district heating). For example, a CHP plant in Metz, France, has a 45MW boiler which burns waste wood biomass. The electricity and heat it generates is sufficient for the needs of a town of 30,000 residences.

Achievable efficiency is 45% electricity, 40% heat and cooling, of the 100% energy from burning fuel. It is therefore a technology which can help reduce greenhouse gases, as well as being economically viable, and adaptable to micro-generation.

EU CHP Directive: European Union’s Cogeneration Directive 2004/08/EC. 11% of EU electricity is cogenerated. Northern countries have more utility of heat as a secondary product of power generation, so they are more advanced in its implementation. Denmark, Holland and Finland (81.8% in 2012) have the greatest proportion of cogeneration plants.